Endoparasite communities of New Zealand Penguins differ over time and among species

Abstract Parasites can provide valuable insights into the ecology and health of their hosts and the state of the surrounding ecosystem. In this study, we describe the helminth parasite communities infecting penguin species in Otago, New Zealand (little blue penguin, Fiordland crested penguin, Snares crested penguin, erect crested penguin and yellow-eyed penguin). We investigate differences in parasite communities among penguin species, and changes over time for little blue penguins. In total, 19 parasite species representing 8 families (Desmidocercidae, Anisakidae, Acuariidae, Capillariidae, Tetrabothriidae, Heterophyidae, Renicolidae and Polymorphidae) were recorded from 121 penguin individuals. Parasite assemblages differed among penguin species, likely reflective of their differences in diet and feeding strategies. We also observed significant changes in the composition of parasite communities of little blue penguins using samples from a 30-year timespan (1993–2023). There was an overall increase in parasite diversity over time, including some species of potential disease concern, which could reflect a shift in prey availability of fish in the area. Our findings contribute to the understanding of penguin ecology and emphasise the use of parasites as indicators of ecological change.